Specific metabolic biomarkers as risk and prognostic factors in colorectal cancer

Advances in genomics,molecular pathology and metabolism have generated many candidate biomarkers of colorectal cancer with potential clinical value.Epidemiological and biological studies suggest a role for adiposity,dyslipidaemia,hyperinsulinemia,altered glucose homeostasis,and elevated expression of insulin-like growth factor(IGF)axis members in the risk and prognosis of cancer.This review discusses some recent past and current approaches being taken by researches in obesity and metabolic disorders.The authors describe three main systems as the most studied metabolic candidates of carcinogenesis:dyslipidemias,adipokines and insulin/IGF axis.However,each of these components is unsuccessful in defining the diseases risk and progression,while their co-occurrence increases cancer incidence and mortality in both men and women.

Hemoglobin Adducts as Biomarkers of Exposure to and metabolic Activation of Carcinogenic Tobacco-Specific Nitrosamines

The carcinogenic tobacco-specific nitrosamines N-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-l-(3-pyridyl)-l-butanone (NNK) form hemoglobin adducts in laboratory animals and humans. These adducts release 4-hydroxy-l-(3-pyridyl)-l-butanone (HPB) upon mild base hydrolysis. HPB released from human hemoglobin can be quantified by gas chromatography-mass spectrometry. It is the only available biochemical marker for determination of exposure to, and metabolic activation of, carcinogens present only in tobacco. Levels of HPB were highest in snuff-dippers, followed by smokers and nonsmokers. Large interindividual variations in adduct levels were observed. The relationship between HPB levels in globin and DNA of rats treated with NNK has been investigated in order to aid in interpretation of the data from humans. These studies have provided the initial database for understanding the metabolic activation of tobacco-specific nitrosamines in humans.

Iron Status of a People Living with HIV in Sub-Saharan Africa Using a Multi-Criteria Approach Based on the Determination of Blood Ferritin, sTfR, CRP and sTfR-F Index

Background: The assessment of iron status using a single biomarker of iron metabolism is not enough sensitive and specific to reliably diagnose iron deficiency associated with multiple comorbidities. The objective of this study was to describe the iron status of people living with HIV in sub-Saharan Africa using a multi-criteria approach based on the determination of blood ferritin, sTfR, CRP and the calculation of sTfR-F index. Methods: This study was conducted using a retrospective panel of 933 sera/plasmas. We determined serum ferritin concentration, serum sTfR concentration, and C-reactive protein (CRP) by immunoturbidimetry for each subject. The sTfR-F index was determined by calculating the sTfR/log ferritin ratio. The statistical test used was Chi2. Results: Regardless of the inflammatory syndrome, we determined 3.80%, 30.29%, and 42.70% iron deficiency based on the separate interpretation of ferritin concentration, sTfR, and sTfR-F calculation, respectively. We used those biomarkers in addition to CRP in an algorithm for the diagnosis of iron deficiency. Subjects without inflammatory syndrome, had iron deficiency of 2.89% (n = 26). Taking into account the presence of an inflammatory syndrome, the frequency obtained was n = 88 (9.78%). Overall, iron deficiency was diagnosed in 114 (12.67%) patients when we used the diagnostic algorithm. Conclusion: The use of diagnostic algorithms combining several biomarkers of iron metabolism and taking into account the presence or absence of an inflammatory syndrome is a good approach to detect a large number of iron deficiencies in a population. Therefore, an assessment of the effectiveness of different diagnostic algorithms is necessary.